Puzzlers around the world are addicted to Sudoku.

To those who try to match up the puzzle's rows, columns and squares with the proper sequence of numbers, the game is either just plain maddening or an eagerly anticipated challenge.

Sudoku, under various names, was published in the United States as far back as 25 years ago. But it became a craze in Japan in 1986, popular in England last fall and turned into an international craze this year.

The Advertiser started running the numerical brain teaser on July 11 on the Coffee Break page in the Island Life section.

If the e-mails from readers are any judge, a craze may be in the making here, too.

"These puzzles are awesome," said one subscriber.

Another reader thanked us for giving him more mental exercise.

And we've heard from a couple of readers convinced that day's puzzle is flawed.

They weren't and puzzlers should know that just like the New York Times crossword, the puzzles start out the week relatively easy and progressively become more difficult.

The Web site for Sudoku promises that all that is needed to solve the puzzles is reasoning and logic.

It also says that puzzlers typically need 10 to 30 minutes to solve the puzzles. So you can judge your own solving time against that!

We're interested in your feedback on the progression of difficulty from Monday through Sunday in the Sudoku puzzles we publish. If you want to weigh in, please e-mail or call me.

Unfortunately, adding a new feature meant that something had to depart from the pages of The Advertiser.

Sudoku took over the space occupied by KidSpot on the Coffee Break page.

KidSpot, a popular feature for younger readers, was moved to the comics page, which had no extra territory.

Something had to give. So to make room for KidSpot, editors chose to cancel Non Sequitur.

Any change in comic strips brings a reaction from readers, and we heard from about three dozen people who were unhappy with the loss of Non Sequitur.

It is rarely an easy decision when comic strips are changed.

"We had to make a tough call on discontinuing Non Sequitur when we made the addition of our new numbers puzzle, Sudoku," said Island Life editor Elizabeth Kieszkowski.

"Non Sequitur was a smart strip, and it was not easy to make this choice, but we know that Sudoku has become a feature of choice for puzzle fans around the globe, and we're hearing from readers that they really enjoy this new addition."

Many unhappy Non Sequitur fans were convinced we at The Advertiser were uncomfortable with Non Sequitur, which comments on public affairs, or just didn't like it. Neither is the case.

We try to put together a comic page that appeals to a range of readers, not one that appeals to our own interests.

We know that across the spectrum of readers, there are strong opinions on comic strips we carry as well as on those we don't.

We try to balance those interests.